I’ve been meaning to post about OpenID for some time now, but have been held back by the fact that I didn’t understand it—a small matter, you might think, but one that even so got in my way.

Now, thanks to man-about-the-internet Simon (isn’t everybody?) Willison, I grasp the thing, and find it to be both more and less useful than I’d imagined.

If you’re terribly keen, you can flip right over to his screencast for the explanation of it all. But if you’ll give me a moment, I’ll try to prepare you with a bit of rationale. The nub of it, at the moment at least, is that OpenID is a labour saving device and, to a small degree, a security measure. Instead of logging in to this and that website with either a fresh userid and password or your precious and ideally secret userid and password, you create an open ID at one of the various sites offering you that opportunity and thereafter use that open ID each time you log in to any (cooperating) website. The ID is a URL (one thing to remember only), which means, by the way, that if you have a domain of your own you can easily set things up to use that as your OpenID—as I’ve done with fodden.com

At the present, there aren’t very many sites that invite you to log in with your OpenID. (One site that gets mentioned all the time as an interesting demo site is Wikitravel, which I’d not known about. A good find.) But it’s early days yet, and there’s been quite a push in the blogosphere to get OpenID adopted more widely. If it does spread, it could be quite useful; and if, as is proposed, software is developed that takes advantage of the fact that you’ll have a single ID that links you to a variety of sites, we may see useful things come of the ability to aggregate your interests.

There are a number of places you can go to to claim an OpenID, a list of which is available on the OpenID Wiki.